The energy that a substance contains is

Imagine you are holding an apple. a. Does this apple have energy? How do you know? b. How could you increase the potential energ

Len [333]

A). The apple has thermal energy, because its temperature is higher
than absolute zero.
It also has chemical energy, because if I eat it, I get a burst of energy
and I become ambitious for a while.
It also has gravitational potential energy, because if I drop it on my foot,
it could bruise one of my piggies.

b). I could increase its potential energy by lifting it higher, like over my head.

c). As long as I'm just holding the apple, it doesn't have any kinetic energy.
I could give it some kinetic energy by throwing it.
Or I could just drop it, and let gravity give it kinetic energy.

7 0

3 years ago

If the moon phase is seen as a waxing crescent moon in london, what phase of the moon would be seen in new york if it's viewed a

Murljashka [212]

Lunar phase is the same wherever on Earth you observe
Last (third) quarter rises at midnight, sets at noon. 
First quarter rises at noon, sets at midnight

4 0

3 years ago

What was the direction of the ball’s velocity

Tju [1.3M]

Part of the question is missing. Here it is:

A 72 g autographed baseball slides off of a 1.3 m high table and strikes the floor a horizontal distance of 0.7m away from the table. The acceleration of gravity is 9.81 m/s2. What was the direction of the ball’s velocity just before it hit the floor?

Answer:

$\theta=-75.7^{\circ}$

Explanation:

The motion of the ball is a projectile motion, which consists of two separate motions:

- A horizontal motion at constant velocity

- A vertical motion at constant acceleration (free fall)

We start by analyzing the vertical motion, to find the time of flight of the ball. This can be done by using the suvat equation

$s=ut+\frac{1}{2}at^2$

where, choosing downward as positive direction:

s =1.3 m is the vertical displacement of the ball

u = 0 is the initial vertical velocity

$a=g=9.8 m/s^2$ is the acceleration of gravity

t is the time

Solving for t,

$t=\sqrt{\frac{2s}{a}}=\sqrt{\frac{2(1.3)}{9.8}}=0.52 s$

Now we can find the final vertical velocity of the ball, using:

$v_y=u+at$

And susbtituting t = 0.52 s, we find

$v_y = 0 +(9.8)(0.52)=5.1 m/s$

It is important to keep in mind that the direction of this velocity is downward, since we chose downward as positive direction.

The horizontal velocity of the ball instead is constant; we know that the ball covers a horizontal distance of

d = 0.7 m

In a time of

t = 0.52 s

So, the horizontal velocity is

$v_x = \frac{0.7}{0.52}=1.3 m/s$

So now we can find the direction of the ball's velocity using:

$\theta=tan^{-1}(\frac{v_y}{v_x})=tan^{-1}(\frac{5.1}{1.3})=75.7^{\circ}$

And since the vertical direction is downward, this means that this velocity is below the horizontal, so the answer is

$\theta=-75.7^{\circ}$

8 0

3 years ago

What is the weight of a bag that has the mass of 18.0kg

Novay_Z [31]

39.6832 pounds would be your answer

8 0

3 years ago

Read 2 more answers

a system that uses reflected radio waves to detect objects and to measure their distance and speed is called

viktelen [127]

Such system is called RADAR (RAdio Detection And Ranging).

The Radar emits radio waves, that are reflected back by the object. Since the speed of the radio waves is known (their speed is equal to the speed of light), by measuring the time the waves take to come back to the source it is possible to infer the distance they covered, and so the distance of the object.

3 0

3 years ago